How are NULL values stored in Hash files?

zulfi123786 · Post by **zulfi123786** » Thu Oct 08, 2009 8:52 am

ArndW · Post by **ArndW** » Thu Oct 08, 2009 9:00 am

A NULL (0x00) can be stored, as can an SQL NULL (0x80). Both are stored as-is in hashed files.

zulfi123786 · Post by **zulfi123786** » Wed Feb 10, 2010 12:16 am

ArndW wrote:A NULL (0x00) can be stored, as can an SQL NULL (0x80). Both are stored as-is in hashed files.

In that case is char(0x00)=@NULL and char(0x80)=@NULL

ArndW · Post by **ArndW** » Wed Feb 10, 2010 3:59 am

No, @NULL represents only one value, namely 0x00. DataStage server/BASIC has no concept of the SQL NULL value, but can represent its ASCII value.

chulett · Post by **chulett** » Wed Feb 10, 2010 7:16 am

There are at least a couple of posts on this subject that I've participated in, one is titled something like 'When is a null not a null?'.

ray.wurlod · Post by **ray.wurlod** » Wed Feb 10, 2010 3:05 pm

0x00 is not @NULL. It is the ASCII NUL byte and can be represented using the function Char(0).

0x80 is @NULL (unless changed, on Windows platforms, because Microsoft uses 0x80 for the Euro symbol). The change is effected in uvconfig.

ArndW · Post by **ArndW** » Wed Feb 10, 2010 3:38 pm

I was too slow today and not thinking! Thanks for correcting that Ray.